Skip to main content
U.S. flag

An official website of the United States government

Official websites use .gov
A .gov website belongs to an official government organization in the United States.

Secure .gov websites use HTTPS
A lock ( ) or https:// means you’ve safely connected to the .gov website. Share sensitive information only on official, secure websites.

Temperature Dependence of Molecular Orientation on the Surfaces of Semi-Fluorinated Polymer Thin Films

Published

Author(s)

Jan Genzer, E Sivaniah, E K. Kramer, J G. Wang, H Koerner, K Char, Christopher K. Ober, B M. DeKoven, Robert A. Bubeck, Daniel A. Fischer, S Sambasivan

Abstract

Near-edge X-ray absorption fine structure is used to investigate the temperature dependence of molecular orientation of semi-fluorinated liquid crystalline (SF-LC) mesogens, which are attached to the modified isoprene backbone of i) a polyisoprene homopolymer, and ii) a diblock copolymer consisting of polystyrene and polyisoprene blocks. Our experiments reveal the existence of two temperature regions in which the surface orientation of the SF-LC mesogens changes abruptly. While the lower temperature surface transition seems to be controlled exclusively by the ordering phenomena originating from the surface, the change in the surface organization of the SF-LC mesogens at higher temperatures can be associated with the bulk LC transition from the smectic-A to the isotropic phase.
Citation
Langmuir
Volume
16
Issue
No. 4

Keywords

co-polymers, fluorinated surfaces, NEXAFS, polymers, thin films

Citation

Genzer, J. , Sivaniah, E. , Kramer, E. , Wang, J. , Koerner, H. , Char, K. , Ober, C. , DeKoven, B. , Bubeck, R. , Fischer, D. and Sambasivan, S. (2000), Temperature Dependence of Molecular Orientation on the Surfaces of Semi-Fluorinated Polymer Thin Films, Langmuir (Accessed May 24, 2024)

Issues

If you have any questions about this publication or are having problems accessing it, please contact reflib@nist.gov.

Created January 31, 2000, Updated October 12, 2021